vendredi 7 octobre 2016

Hurricane forecasters use many different types of data to forecast a storm’s intensity and track. NASA satellites and airborne instruments, including several developed and operated by NASA’s Jet Propulsion Laboratory, Pasadena, California, contribute to scientists’ understanding of tropical cyclones and help improve forecasts.

Here are some of the latest data on Hurricane Matthew from JPL-developed satellites and instruments:

A hurricane is like an engine: the more it revs up, the warmer it gets. A JPL-developed microwave sounder called the High-Altitude Monolithic Microwave Integrated Circuit Sounding Radiometer (HAMSR) can measure a hurricane’s atmospheric temperature and humidity, even in the presence of clouds, and can also be used to measure rain and ice from Earth’s surface to the top of the storm’s convective clouds.

HAMSR has been flying repeatedly over Hurricane Matthew aboard a NASA Global Hawk unmanned aircraft as part of the National Oceanic and Atmospheric Administration’s Sensing Hazards with Operational Unmanned Technology (SHOUT) field campaign.

The image montage shows observations from HAMSR as it crisscrossed above Matthew at an altitude of about 55,000 feet (16,764 meters) in the early morning hours of Oct. 7, as the storm was approaching Florida’s east coast. The “swaths” are about 30 miles (48 kilometers) wide. The large image at right shows the temperature of the upper atmosphere above Matthew’s core. The temperature is proportional to the storm’s intensity -- the higher the temperature over the core relative to the environment, the more intense the storm. The HAMSR data are overlaid atop a ground-based radar image and satellite visible image. Red colors (warm) depict areas without clouds, while blue colors (very cold) represent scattering due to ice in the atmosphere and heavy precipitation. The image in the lower left shows the HAMSR data alone. The image in the upper left was taken by a camera aboard the Global Hawk.

As the Global Hawk prepared to return home to NASA’s Armstrong Flight Research Center in Edwards, California, it captured one last look inside Matthew’s spiral cloud bands. The red colors show cloud bands without precipitation, while blue colors show rain bands. The Global Hawk’s location is just past the eye (the red circle in the center of the image).

The HAMSR data were transmitted in real time via a communications satellite to the ground, where they were immediately processed and shared with the SHOUT scientists, who use them for situational awareness. They were also posted on a public web server. Images and data were also shared with forecasters at the NOAA/National Weather Service’s National Hurricane Center.

The radiometer instrument on NASA’s Soil Moisture Active Passive (SMAP) satellite can measure a hurricane’s wind speeds. SMAP observations of Hurricane Matthew, taken at 4:52 a.m. PDT (7:52 a.m. EDT and 11:52 UTC) on Oct 7, found wind speeds up to 132 mph (59 meters per second). SMAP has excellent sensitivity to extreme winds, far beyond that of typical scatterometer instruments now in orbit. This is because SMAP’s L-band is not affected by rain and can provide accurate wind speeds regardless of rain conditions.

Image above: At 11:29 p.m. PDT on Oct. 6 (2:29 a.m. EDT on Oct. 7), NASA’s Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite produced this false-color infrared image of Matthew as the storm moved up Florida’s central coast. The image shows the temperature of Matthew’s cloud tops or the surface of Earth in cloud-free regions, with the most intense thunderstorms shown in purples and blues. Image Credits: NASA/JPL-Caltech.

At 11:29 p.m. PDT on Oct. 6 (2:29 a.m. EDT and 6:29 UTC on Oct. 7), NASA’s Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite produced this false-color infrared image of Matthew as the storm moved up the coast of central Florida. Hurricane Nicole is visible to the right in the Atlantic.

The AIRS data create an accurate 3-D map of atmospheric temperature, water vapor and clouds, data that are useful to forecasters. The image shows the temperature of Matthew’s cloud tops or the surface of Earth in cloud-free regions. The coldest cloud-top temperatures appear in purple, indicating towering cold clouds and heavy precipitation. The infrared signal of AIRS does not penetrate through clouds. Where there are no clouds, AIRS reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

NASA’s OSIRIS-REx spacecraft fired its Trajectory Correction Maneuver (TCM) thrusters for the first time Friday in order to slightly adjust its trajectory on the outbound journey from Earth to the asteroid Bennu. The spacecraft’s planned first Trajectory Correction Maneuver (TCM-1) began at 1 p.m. EDT and lasted for approximately 12 seconds. The maneuver changed the velocity of the spacecraft by 1.1 mile per hour (50 centimeters per second) and used approximately 18 ounces (.5 kilogram) of fuel. The spacecraft is currently about 9 million miles (14.5 million kilometers) from Earth.

TCM-1 was originally included in the spacecraft’s flight plan to fine-tune its trajectory if needed after the mission’s Sept. 8 launch. The ULA Atlas V’s launch performance was so accurate, however, that the spacecraft’s orbit had no practical need for correction. Instead, the OSIRIS-REx mission team used the Oct. 7 maneuver to test the TCM thrusters and as practice to prepare for a much larger propulsive maneuver scheduled in December.

The mission had allocated approximately 388 ounces (11 kilograms) of propellant for TCM-1 to create a velocity change of up to 26 miles per hour (11.6 meters per second), had it been necessary. The unused propellant from this event provides more fuel margin for the spacecraft’s asteroid proximity operations once OSIRIS-REx arrives at Bennu.

OSIRIS-REx arrives at Bennu. Image Credit: NASA

To track today’s maneuver, the OSIRIS-REx mission’s navigation team monitored the Doppler shift in radio signals between the spacecraft and the Deep Space Network antenna at the Goldstone Observatory in California. After 44 seconds—the current one-way light time delay between the spacecraft and Earth—the team received the first maneuver data from the spacecraft. Over the next week, the navigation team will process daily spacecraft tracking data to determine the precise effect of the burn.

The OSIRIS-REx spacecraft has four different kinds of thrusters providing considerable redundancy in its ability to maneuver on its way to the surface of Bennu and back. OSIRIS-REx began using its Attitude Control System (ACS) thrusters shortly after launch to keep the spacecraft oriented, so that its solar arrays point toward the sun and its communication antennas point toward Earth. Today was the first use of its larger Trajectory Correction Maneuver (TCM) thrusters. In December OSIRIS-REx will use its largest thrusters, the Main Engine (ME) thrusters, to target the spacecraft for its Earth Gravity Assist scheduled for Sept. 22, 2017. Its smallest thrusters, the Low Thrust Reaction Engine Assembly (LTR) thrusters, will be used for the delicate maneuvers close to the surface of the asteroid Bennu.

NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s observation planning and processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing spacecraft flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

Along with the visible light and warmth constantly emitted by our sun comes a whole spectrum of X-ray and ultraviolet radiation that streams toward Earth. A new CubeSat – a miniature satellite that provides a low-cost platform for missions – is now in space observing a particular class of X-ray light that has rarely been studied.

MinXSS CubeSat Brings New Information to Study of Solar Flares

Video above: This video was made using MinXSS data from a low-intensity solar flare that occurred on July 21, 2016, from 1:33-2:23 UT, and imagery from NASA’s SDO. On the graph, pre-flare levels are shown in red, and the yellow line is the flare spectrum in real-time. MinXSS saw energy and brightness increase during the solar flare, which is apparent in the corresponding SDO images when a loop of solar material rises from an active region on the sun and shines brightly. Scientists use these flare measurements to trace the temperature, density and abundance of solar flare material during a flare. Video Credits: NASA’s Goddard Space Flight Center/LASP/MinXSS/SDO/Joy Ng, producer.

On June 9, 2016, the NASA-funded, bread loaf-sized Miniature X-Ray Solar Spectrometer, or MinXSS, CubeSat began science operations, collecting data on soft X-rays. Watch the video to see a low-intensity solar eruption – a solar flare – from July 21, 2016. The flare imagery was captured by NASA's Solar Dynamics Observatory; the MinXSS data shown on the right shows the soft X-rays observed in near-Earth space by the CubeSat before and during the flare.

Animation above: Taken by astronauts on May 16, 2016, these images show a CubeSat deployment from the International Space Station. The bottom-most CubeSat is the NASA-funded MinXSS CubeSat, built by the University of Colorado, Boulder. Image Credit: NASA.

Each type of solar radiation conveys unique information about the physics underlying solar flares. This data reveals the temperature, density and abundance of solar flare material, all critical factors for determining how flares evolve and heat the sun’s atmosphere. Ultimately, solar eruptions impact Earth’s upper atmosphere: X-rays from the sun can disturb near-Earth space, interfering with GPS, radio and other communication signals. The class of X-rays that MinXSS observes are particularly important for their influence in the level of the upper atmosphere called the ionosphere.

This video shows how dynamic the solar atmosphere can become, and highlights that MinXSS has great sensitivity to observe even the weak flares. These observations exemplify the goals of the six-month mission, which began after the spacecraft was deployed from the International Space Station in May 2016 and has already met its criteria for comprehensive success. The University of Colorado, Boulder, manages MinXSS under the direction of principal investigator Tom Woods.

Image above: This scene from NASA's Mars rover Opportunity shows "Wharton Ridge," which forms part of the southern wall of "Marathon Valley" on the rim of Endeavour Crater. The ridge's name honors the memory of astrobiologist Robert A. Wharton (1951-2012). The scene is presented in approximately true color. Image Credits: NASA/JPL-Caltech/Cornell/Arizona State Univ.

NASA's Opportunity Mars rover will drive down a gully carved long ago by a fluid that might have been water, according to the latest plans for the 12-year-old mission. No Mars rover has done that before.

The longest-active rover on Mars also will, for the first time, visit the interior of the crater it has worked beside for the last five years. These activities are part of a two-year extended mission that began Oct. 1, the newest in a series of extensions going back to the end of Opportunity's prime mission in April 2004.

Image above: This scene from NASA's Mars rover Opportunity shows "Wharton Ridge," on the western rim of Endeavour Crater. The ridge's name honors the memory of astrobiologist Robert A. Wharton (1951-2012). The scene is presented in enhanced color to make differences in surface materials more easily visible. Image Credits: NASA/JPL-Caltech/Cornell/Arizona State Univ.

Opportunity launched on July 7, 2003 and landed on Mars on Jan. 24, 2004 (PST), on a planned mission of 90 Martian days, which is equivalent to 92.4 Earth days.

"We have now exceeded the prime-mission duration by a factor of 50," noted Opportunity Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, California. "Milestones like this are reminders of the historic achievements made possible by the dedicated people entrusted to build and operate this national asset for exploring Mars."

Opportunity begins its latest extended mission in the "Bitterroot Valley" portion of the western rim of Endeavour Crater, a basin 14 miles (22 kilometers) in diameter that was excavated by a meteor impact billions of years ago. Opportunity reached the edge of this crater in 2011 after more than seven years of investigating a series of smaller craters. In those craters, the rover found evidence of acidic ancient water that soaked underground layers and sometimes covered the surface.

Image above: This Sept. 21, 2016, scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity shows "Spirit Mound" overlooking the floor of Endeavour Crater. The mound stands near the eastern end of "Bitterroot Valley" on the western rim of the crater, and this view faces eastward. Image Credits: NASA/JPL-Caltech/Cornell/Arizona State Univ.

The gully chosen as the next major destination slices west-to-east through the rim about half a mile (less than a kilometer) south of the rover's current location. It is about as long as two football fields.

"We are confident this is a fluid-carved gully, and that water was involved," said Opportunity Principal Investigator Steve Squyres of Cornell University, Ithaca, New York. "Fluid-carved gullies on Mars have been seen from orbit since the 1970s, but none had been examined up close on the surface before. One of the three main objectives of our new mission extension is to investigate this gully. We hope to learn whether the fluid was a debris flow, with lots of rubble lubricated by water, or a flow with mostly water and less other material."

Image above: This Sept. 21, 2016, scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity shows "Spirit Mound" overlooking the floor of Endeavour Crater. The mound stands near the eastern end of "Bitterroot Valley" on the western rim of the crater, and this view faces eastward. Image Credits: NASA/JPL-Caltech/Cornell/Arizona State Univ.

The team intends to drive Opportunity down the full length of the gully, onto the crater floor. The second goal of the extended mission is to compare rocks inside Endeavour Crater to the dominant type of rock Opportunity examined on the plains it explored before reaching Endeavour.

"We may find that the sulfate-rich rocks we've seen outside the crater are not the same inside," Squyres said. "We believe these sulfate-rich rocks formed from a water-related process, and water flows downhill. The watery environment deep inside the crater may have been different from outside on the plain -- maybe different timing, maybe different chemistry."

Image above: This stereo scene from NASA's Mars Exploration Rover Opportunity shows "Spirit Mound" overlooking the floor of Endeavour Crater. The view appears three-dimensional when seen through blue-red glasses with the red lens on the left. Image Credits: NASA/JPL-Caltech/Cornell/Arizona State Univ.

The rover team will face challenges keeping Opportunity active for another two years. Most mechanisms onboard still function well, but motors and other components have far exceeded their life expectancy. Opportunity's twin, Spirit, lost use of two of its six wheels before succumbing to the cold of its fourth Martian winter in 2010. Opportunity will face its eighth Martian winter in 2017. Use of Opportunity's non-volatile "flash" memory for holding data overnight was discontinued last year, so results of each day's observations and measurements must be transmitted that day or lost.

In the two-year extended mission that ended last month, Opportunity explored the "Marathon Valley" area of Endeavour's western rim, documenting the geological context of water-related minerals that had been mapped there from orbital observations. Last month, the rover drove through "Lewis and Clark Gap," a low point in the wall separating Marathon Valley from Bitterroot Valley. A recent color panorama from the rover features "Wharton Ridge," which extends eastward from the gap.

Image above: This map show a portion of Endeavour Crater's western rim that includes the "Marathon Valley" area investigated intensively by NASA's Mars Exploration Rover Opportunity in 2015 and 2016, and a fluid-carved gully that is a destination to the south for the mission. Image Credits: NASA/JPL-Caltech/Univ. of Arizona.

This week, Opportunity is investigating rock exposures next to "Spirit Mound," a prominent feature near the eastern end of Bitterroot Valley. The third main science goal of the new extended mission is to find and examine rocks from a geological layer that was in place before the impact that excavated Endeavour Crater. The science team has not yet determined whether the mound area will provide rocks that old.

Mars Exploration Rover. Image Credits: NASA/JPL-Caltech

Opportunity and NASA’s next-generation Mars rover, Curiosity, as well as three active NASA Mars orbiters, and surface missions to launch in 2018 and 2020 are steps in NASA's Journey to Mars, on track for sending humans there in the 2030s. JPL, a division of Caltech in Pasadena, California, built Opportunity and manages the mission for NASA's Science Mission Directorate, Washington. For more information about Opportunity, visit:

This Hubble image shows the central region of a spiral galaxy known as NGC 247. NGC 247 is a relatively small spiral galaxy in the southern constellation of Cetus (The Whale). Lying at a distance of around 11 million light-years from us, it forms part of the Sculptor Group, a loose collection of galaxies that also contains the more famous NGC 253 (otherwise known as the Sculptor Galaxy).

NGC 247’s nucleus is visible here as a bright, whitish patch, surrounded by a mixture of stars, gas and dust. The dust forms dark patches and filaments that are silhouetted against the background of stars, while the gas has formed into bright knots known as H II regions, mostly scattered throughout the galaxy’s arms and outer areas.

This galaxy displays one particularly unusual and mysterious feature — it is not visible in this image, but can be seen clearly in wider views of the galaxy, such as a picture from ESO’s MPG/ESO 2.2-meter telescope. The northern part of NGC 247’s disc hosts an apparent void, a gap in the usual swarm of stars and H II regions that spans almost a third of the galaxy’s total length.

There are stars within this void, but they are quite different from those around it. They are significantly older, and as a result much fainter and redder. This indicates that the star formation taking place across most of the galaxy’s disk has somehow been arrested in the void region, and has not taken place for around one billion years. Although astronomers are still unsure how the void formed, recent studies suggest it might have been caused by gravitational interactions with part of another galaxy.

NASA’s Global Hawk aircraft was deployed to Florida from Armstrong Flight Research Center at Edwards, CA. on Oct. 6 to monitor and take scientific measurements of Hurricane Matthew. The unmanned Global Hawk will gather scientific data in support of NOAA’s Sensing Hazards with Operational Unmanned Technology (SHOUT) mission.

Hurricane Matthew, currently an extremely dangerous Category 4 storm on the Saffir-Simpson Hurricane Wind Scale, continues to bear down on the southeastern United States. At 11:27 a.m. PDT (2:27 p.m. EDT and 18:23 UT) today, NASA’s Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite observed the storm as its eye was passing over the Bahamas. The AIRS false-color infrared image shows that the northeast and southwest quadrants of the storm had the coldest cloud tops, denoting the regions of the storm where the strongest precipitation was occurring at the time. Data from the Advanced Microwave Sounding Unit (AMSU), another of AIRS’ suite of instruments, indicate that the northeast quadrant, which appears smaller in the infrared image, likely had the most intense rain bands at the time. The AIRS infrared image shows that at the time of the image the storm had full circulation, with a small eye surrounded by a thick eye wall.

Many smaller laboratories that still perform IVD manually are also trying totake this step towards automation, but find that existing high-throughput units are too costly.

The answer is orbiting Earth

It wasn’t until biotech company Fujirebio Europe joined with Belgium’s Verhaert, involved in Europe’s space programmes for many years, that the answer was found – and from a completely different direction.

The unit developed by Verhaertfor the Biolab research facility in Europe’s Columbus laboratory on the International Space Station turned out to provide a solution for low-throughput IVD. It is now improving the diagnosis of infectious diseases and cancers here on Earth.

Columbus laboratory

Having to operate on the Space Station, and with the limited time available to astronauts to perform experiments, space laboratories require automated devices with long lifetimes and low maintenance and calibration needs.

Space experiments are typically done on a small scale and require a high level of accuracy. Temperature and risk of contamination must also be carefully managed.

Biolab

To simplify Biolab experiments in space, Verhaert designed and built a unit for precisely controlling the application of liquid nutrients onto a sample strip.

Reusing this approach and their knowhow on precision dosing and contamination control enabled Verhaert to automate the previously manual work for low-throughput IVD.

“Many general laboratories performing low-throughput IVD have expressed their wish to move towards more automation and integration of their workflows,” said Christiaan De Wilde, CEO at Fujirebio Europe.

Automated testing

“These laboratories have been looking in vain for accessible solutions to help them take the important first step towards automation.”

The Verhaert space design features a completely new automatic testing mechanism that is cheaper to use, thanks to a higher processing speed, the elimination of maintenance and calibration, and a more efficient use of reagents.

Small laboratories typically perform IVDs manually, which can now be automated, reducing the time needed and the cost. The absence of maintenance and calibration result in lower operating costs.

Installing experiment in Biolab

In August 2015, Fujirebio Europe launched it into the in vitro diagnostics market to handle just 10 IVD strips at a time.

“This diagnostics device is using the same handling mechanism and volumetric dosing architecture we developed for the laboratories on Space Station,” says Sam Waes from Verhaert, also the Belgium broker to ESA's Technology Transfer Programme.

“Thanks to this space technology transfer, it has a level of accuracy that is similar to the higher-throughput processors, typically of 48 strips, at a fraction of the cost.”

This week, the commands that will govern the Schiaparelli lander’s descent and touchdown on Mars were uploaded to ESA’s ExoMars spacecraft, enroute to the Red Planet.

The Trace Gas Orbiter has been carrying the Schiaparelli entry, descent and landing demonstrator since launch on 14 March. Upon arrival on 19 October, Schiaparelli will test the technology needed for Europe’s 2020 rover to land, while its parent craft brakes into an elliptical orbit around Mars.

This week’s uploading was conducted by the Orbiter team working at ESA’s mission control in Darmstadt, Germany, and marked a significant milestone in readiness for arrival.

Final 'sim' training

Schiaparelli’s operations are governed by time-tagged stored commands, ensuring that the lander can conduct its mission even when out of contact with any of the Mars orbiters that will serve as data relays.

Automated operation also ensures that the lander will revive from its power-saving sleep periods on the surface in time for communication links.

Telling Schiaparelli what to do

The commands were uploaded in two batches. The first, containing the hibernation wake-up timers and the surface science instrument timeline, was uploaded on 3 October. The second, containing the rest of the mission command sequence, was uploaded to the module on 7 October.

“Uploading the command sequences is a milestone that was achieved following a great deal of intense cooperation between the mission control team and industry specialists,” says Orbiter flight director Michel Denis.

Schiaparelli on Mars

One of the most crucial moments will be the moment of landing, set for 14:48:11 GMT (16:48:11 CEST) on 19 October. Now that this time has been fixed, the rest of the commands will play out in sequence counting down or up.

During landing, these commands include ejecting the front and back aeroshells, operating the descent sensors, deploying the braking parachute and activating three groups of hydrazine thrusters to control its touchdown speed.

A radar will measure Schiaparelli’s height above the surface starting at about 7 km. At around 2 m, Schiaparelli will briefly hover before cutting its thrusters, leaving it to fall freely.

Once safely on the surface, the timeline will operate the science instruments for a planned two days – and possibly longer.

Schiaparelli’s descent to Mars

The science activities are designed to make the most of the limited energy available from the batteries, so they will be performed in set windows rather than continuously – typically, for six hours each day.

The timeline will also switch on the module’s transmitter during a series of fixed slots to send recorded data up to ESA and NASA orbiters passing overhead, which will then transmit the data to Earth.

These relay slots include 32 by NASA craft: 18 by the Mars Reconnaissance Orbiter, eight by Odyssey and six by Maven. ESA’s Mars Express will make 14 overflights.

jeudi 6 octobre 2016

Today, at the 39th meeting of the International Civil Aviation Organization, 191 countries reached a global climate deal to reduce carbon emissions from aviation. At the same time, NASA is working to create new experimental aircraft that will demonstrate new “green aviation” technology intended to dramatically reduce fuel use, emissions and noise – with the goal of cutting emissions from the nation’s commercial aircraft fleet by more than 50 percent, while also reducing perceived noise levels near airports to one-half the level of the quietest aircraft flying today.

To that end, NASA recently awarded six-month contracts to four companies, who will each define the technical approach, schedule, and cost for one or more large-scale, subsonic X-plane concepts. These concepts are in support of NASA’s ultra-efficient subsonic transport research goals.

The companies are Aurora Flight Sciences Corporation of Manassas, VA; Dzyne Technologies Incorporated of Fairfax, VA; Lockheed Martin Aeronautics Company of Ft. Worth, TX; and The Boeing Company of Hazelwood, MO.

“Engaging these contractors now to gather this information will help us move forward efficiently and expeditiously when we’re ready to commit to building the X-planes themselves,” said Ed Waggoner, NASA’s Integrated Aviation Systems Program director.

Each company is to detail their specific X-plane system requirements for a piloted experimental aircraft capable of sustained, two to three hours of powered high subsonic flight, as well as conducting at least two research flight sorties per week over the course of a year-long program.

The requested information is to be built around a plan that would see the selected experimental aircraft eventually flying no later than 2021.

NASA’s return to flying large-scale X-plane technology demonstrators – a staple of its aeronautical research heritage – is part of New Aviation Horizons, an ambitious 10-year accelerated research plan developed and announced by NASA earlier this year.

The five X-plane concepts envisioned for possible further development and the contractor responsible for providing NASA with the required information include:

- Aurora Flight Services for the D8 “Double Bubble,” a twin-aisle, largely composite airliner in which the fuselage is shaped to provide lift – enabling smaller wings – and the jet engines are mounted atop the rear tail area, which takes advantage of the air flow over the aircraft to both improve engine efficiency and reduce noise in the cabin and on the ground below.

- Dzyne Technologies for a smaller regional jet-sized aircraft that features a blended wing body (BWB) design in which the lines of a traditional tube and wing airliner are shaped to become one continuous line in which the seam between the wing and fuselage is nearly indistinguishable. As an aerodynamic shape, this configuration increases lift and reduces drag.

- Lockheed Martin for its Hybrid Wing Body, which includes features of the BWB on the forward part of the fuselage but has a more conventional looking T-shaped tail, with its jet engines mounted on the side of the hull but above the blended wing. Increased lift, reduced drag and quieter operations are all potential benefits.

- Boeing for both its BWB concept – versions of which the company has flight tested with its subscale X-48 program in partnership with NASA – and a Truss-Braced Wing concept, which features a very long, aerodynamically efficient wing that is held up on each side by a set of trusses connecting the fuselage to the wing. Otherwise the aircraft appears more conventional than the other X-plane concepts under consideration.

Preliminary design work already has begun on a half-scale X-plane called the Quiet Supersonic Technology, or QueSST, a piloted supersonic aircraft that generates a soft thump, rather than the disruptive boom currently associated with supersonic flight.

Work also is underway on the X-57 Maxwell, a general aviation-sized electric research airplane. Maxwell will fly for the first time in early 2018 and demonstrate battery powered, distributed electric propulsion. Transport-sized electric aircraft could reduce energy use by more than 60 percent and harmful emissions by more than 90 percent. This was the first project to get an X-plane number designation in a decade.

NASA’s other green aviation initiatives include reducing airline emissions and flight delays. Working in partnership with airlines and air traffic controllers at the Charlotte Douglas International Airport in North Carolina, NASA is beginning the first-of-a-kind demonstration of new technologies that coordinate operational schedules for aircraft arrivals, departures, and taxiing.

Great balls of fire! NASA's Hubble Space Telescope has detected superhot blobs of gas, each twice as massive as the planet Mars, being ejected near a dying star. The plasma balls are zooming so fast through space it would take only 30 minutes for them to travel from Earth to the moon. This stellar "cannon fire" has continued once every 8.5 years for at least the past 400 years, astronomers estimate.

The fireballs present a puzzle to astronomers, because the ejected material could not have been shot out by the host star, called V Hydrae. The star is a bloated red giant, residing 1,200 light-years away, which has probably shed at least half of its mass into space during its death throes. Red giants are dying stars in the late stages of life that are exhausting their nuclear fuel that makes them shine. They have expanded in size and are shedding their outer layers into space.

Images above: This four-panel graphic illustrates how the binary-star system V Hydrae is launching balls of plasma into space. Panel 1 shows the two stars orbiting each other. One of the stars is nearing the end of its life and has swelled in size, becoming a red giant. In panel 2, the smaller star's orbit carries the star into the red giant's expanded atmosphere. As the star moves through the atmosphere, it gobbles up material from the red giant, which settles into a disk around the star. The buildup of material reaches a tipping point and is eventually ejected as blobs of hot plasma along the star's spin axis, shown in panel 3. This ejection process is repeated every eight years, the time it takes for the orbiting star to make another pass through the bloated red giant's envelope, shown in panel 4. Images Credits: NASA, ESA, and A. Feild (STScI).

The current best explanation suggests the plasma balls were launched by an unseen companion star. According to this theory, the companion would have to be in an elliptical orbit that carries it close to the red giant's puffed-up atmosphere every 8.5 years. As the companion enters the bloated star's outer atmosphere, it gobbles up material. This material then settles into a disk around the companion, and serves as the launching pad for blobs of plasma, which travel at roughly a half-million miles per hour.

This star system could be the archetype to explain a dazzling variety of glowing shapes uncovered by Hubble that are seen around dying stars, called planetary nebulae, researchers say. A planetary nebula is an expanding shell of glowing gas expelled by a star late in its life.

"We knew this object had a high-speed outflow from previous data, but this is the first time we are seeing this process in action," said Raghvendra Sahai of NASA's Jet Propulsion Laboratory in Pasadena, California, lead author of the study. "We suggest that these gaseous blobs produced during this late phase of a star's life help make the structures seen in planetary nebulae."

Hubble observations over the past two decades have revealed an enormous complexity and diversity of structure in planetary nebulae. The telescope's high resolution captured knots of material in the glowing gas clouds surrounding the dying stars. Astronomers speculated that these knots were actually jets ejected by disks of material around companion stars that were not visible in the Hubble images. Most stars in our Milky Way galaxy are members of binary systems. But the details of how these jets were produced remained a mystery.

"We want to identify the process that causes these amazing transformations from a puffed-up red giant to a beautiful, glowing planetary nebula," Sahai said. "These dramatic changes occur over roughly 200 to 1,000 years, which is the blink of an eye in cosmic time."

Sahai's team used Hubble's Space Telescope Imaging Spectrograph (STIS) to conduct observations of V Hydrae and its surrounding region over an 11-year period, first from 2002 to 2004, and then from 2011 to 2013. Spectroscopy decodes light from an object, revealing information on its velocity, temperature, location, and motion.

The data showed a string of monstrous, super-hot blobs, each with a temperature of more than 17,000 degrees Fahrenheit - almost twice as hot as the surface of the sun.

The researchers compiled a detailed map of the blobs' location, allowing them to trace the first behemoth clumps back to 1986. "The observations show the blobs moving over time," Sahai said. "The STIS data show blobs that have just been ejected, blobs that have moved a little farther away, and blobs that are even farther away." STIS detected the giant structures as far away as 37 billion miles away from V Hydrae, more than eight times farther away than the Kuiper Belt of icy debris at the edge of our solar system is from the sun.

The blobs expand and cool as they move farther away, and are then not detectable in visible light. But observations taken at longer sub-millimeter wavelengths in 2004, by the Submillimeter Array in Hawaii, revealed fuzzy, knotty structures that may be blobs launched 400 years ago, the researchers said.

Based on the observations, Sahai and his colleagues Mark Morris of the University of California, Los Angeles, and Samantha Scibelli of the State University of New York at Stony Brook developed a model of a companion star with an accretion disk to explain the ejection process.

"This model provides the most plausible explanation because we know that the engines that produce jets are accretion disks," Sahai explained. "Red giants don't have accretion disks, but many most likely have companion stars, which presumably have lower masses because they are evolving more slowly. The model we propose can help explain the presence of bipolar planetary nebulae, the presence of knotty jet-like structures in many of these objects, and even multipolar planetary nebulae. We think this model has very wide applicability."

A surprise from the STIS observation was that the disk does not fire the monster clumps in exactly the same direction every 8.5 years. The direction flip-flops slightly from side-to-side to back-and-forth due to a possible wobble in the accretion disk. "This discovery was quite surprising, but it is very pleasing as well because it helped explain some other mysterious things that had been observed about this star by others," Sahai said.

Hubble orbiting Earth. Video Credit: ESA

Astronomers have noted that V Hydrae is obscured every 17 years, as if something is blocking its light. Sahai and his colleagues suggest that due to the back-and-forth wobble of the jet direction, the blobs alternate between passing behind and in front of V Hydrae. When a blob passes in front of V Hydrae, it shields the red giant from view.

"This accretion disk engine is very stable because it has been able to launch these structures for hundreds of years without falling apart," Sahai said. "In many of these systems, the gravitational attraction can cause the companion to actually spiral into the core of the red giant star. Eventually, though, the orbit of V Hydrae's companion will continue to decay because it is losing energy in this frictional interaction. However, we do not know the ultimate fate of this companion."

The team hopes to use Hubble to conduct further observations of the V Hydrae system, including the most recent blob ejected in 2011. The astronomers also plan to use the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to study blobs launched over the past few hundred years that are now too cool to be detected with Hubble.

The team's results appeared in the August 20, 2016, issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt,

Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

When you need tools or parts for something you're working on around the house, you head to the nearest hardware store. Space travelers don't have that luxury and may have to make their own tools and parts on long duration missions like the journey to Mars. Scientists and engineers at NASA's Marshall Space Flight Center in Huntsville, Alabama, are using data from International Space Station experiments to study liquids that may be used to help make valuable tools when exploring deep space.

Image above: Experiment sample trays on MISSE-8 attached to the exterior of the International Space Station in 2013. These trays held the ionic liquid epoxy samples that could help build composite cryogenic tanks for future spacecraft. Image Credit: NASA.

For a decade, the Materials International Space Station Experiments (MISSE) were attached to the outside of the space station, where more than 4,000 materials were exposed to the harsh space environment. This included a special class of liquids, called ionic liquids, and a novel epoxy that scientists are studying to learn how these liquids tolerate the environment outside the orbiting laboratory. The members of this family of fluids have low melting points, and are not as flammable as many conventional chemicals. They also have extremely low vapor pressures, meaning they don’t easily evaporate and are easier to retain in the vacuum of space.

“Because of their unique chemistry, we can use ionic liquids to extract both metals and oxygen from lunar or Martian soil at about the same temperature you’d bake a cake,” said Laurel Karr, a materials scientist at the Marshall Center. "The metals could then be used in a 3D printer for needed parts, and the oxygen could be used for life support or propulsion."

Ionic liquids could be used as chemical drills to dissolve regolith on the surface of Mars, said Karr, thus extending the life of drill bits that future explorers, both human and robotic, would normally use to probe the Martian surface.

“We drill into the surface of a planet or asteroid to acquire samples for geological investigations," said Karr. "With this fluid, we could bring up samples in a liquid form for chemical analyses right there on the drill site.”

NASA is interested in these ionic liquids not only for their many uses for exploration missions, but also because they are environmentally-friendly chemicals. Metal extraction technology using the liquid could remove precious metals from ore without the environmental impact of some current methods used on Earth. For example, nickel is conventionally processed by smelting the material at 1,350 degrees Celsius and using sulfuric acid, which is impractical in an enclosed spacecraft due to the toxicity of the acid. Ionic liquid can remove nickel from a meteorite under 200 degrees Celsius.

Scientists are also testing ionic liquids as part of a life support method in space by extracting carbon dioxide from the air and breaking it down to create oxygen for breathing and methane for propulsion.

Many of the ionic liquids can even be filtered and recreated using electrolysis and hydrogen, making them useful recyclable materials in space and on Earth.

One type of ionic liquids that are of particular interest are epoxies.
Richard Grugel, a materials scientist at Marshall, and his colleagues
have been systematically studying epoxies made from ionic liquids,
finding them to be very strong, able to bind well with carbon fiber and
resist the extreme temperature of cryogenic liquid oxygen and hydrogen.

ISS - International Space Station. Image Credit: NASA

In 2013, two different ionic liquid-based epoxies were flown on MISSE-8. After two years of exposure to the space environment, the epoxies were recovered and returned to Earth on a SpaceX Dragon spacecraft. Examination of the liquid samples showed some darkening due to solar ultraviolet radiation, but no cracking or de-bonding, and no change in weight or adhesion.

"These attributes suggest the epoxies could be used to make carbon-fiber composite tanks for cryogenic liquid storage," said Grugel. "This can provide a significant weight reduction over aluminum ones currently used to launch spacecraft."

Microcracking can lead to leaking, and has been a challenge with early
composite cryogenic tank designs. Testing is underway at Marshall on
composite overwrap pressure vessels -- small metal tanks wrapped with
commercial carbon fiber using ionic liquid epoxy -- to determine if the
ionic liquid is a viable material to construct these tanks and make them
stronger.

“Studies are showing this family of versatile liquids
could not only be used to build and repair the spacecraft to get us to
Mars, but also help us survive and make new discoveries after we
arrive,” said Grugel.

Space Station Live: Green Chemistry for the Red Planet

Video above: Laurel Karr and Richard Grugel, two materials scientists at NASA's Marshall Space Flight Center talk about the Materials on the International Space Station Experiment during a recent episode of Space Station Live on NASA-TV. The investigation is shedding light on ionic liquids, which may prove to be a valuable tool when it comes to designing tanks for spacecraft or extracting oxygen and other elements from the Martian soil. It’s a special class of liquids that are also environmentally friendly.

As MISSE demonstrates, science takes time, and research results often keep paying off decades after experiment samples are returned to Earth. The MISSE project has made it possible to evaluate the performance, stability and long-term survivability of materials and components used by NASA, commercial companies and the U.S. Department of Defense. Many spacecraft safely operating today have MISSE to thank for successful operations, because they are made of the most suitable materials for the space environment. The first Martian explorers may have MISSE to thank for innovative materials and processes that help them survive on the red planet.

Global dust storms on Mars could soon become more predictable -- which would be a boon for future astronauts there -- if the next one follows a pattern suggested by those in the past.

A published prediction, based on this pattern, points to Mars experiencing a global dust storm in the next few months. "Mars will reach the midpoint of its current dust storm season on October 29th of this year. Based on the historical pattern we found, we believe it is very likely that a global dust storm will begin within a few weeks or months of this date," James Shirley, a planetary scientist at NASA's Jet Propulsion Laboratory, Pasadena, California.

Image above: Two 2001 images from the Mars Orbiter Camera on NASA's Mars Global Surveyor orbiter show a dramatic change in the planet's appearance when haze raised by dust-storm activity in the south became globally distributed. The images were taken about a month apart. Image credits: NASA/JPL-Caltech/MSSS.

Local dust storms occur frequently on Mars. These localized storms occasionally grow or coalesce to form regional systems, particularly during the southern spring and summer, when Mars is closest to the sun. On rare occasions, regional storms produce a dust haze that encircles the planet and obscures surface features beneath. A few of these events may become truly global storms, such as one in 1971 that greeted the first spacecraft to orbit Mars, NASA's Mariner 9. Discerning a predictable pattern for which Martian years will have planet-encircling or global storms has been a challenge.

The most recent Martian global dust storm occurred in 2007, significantly diminishing solar power available to two NASA Mars rovers then active halfway around the planet from each other -- Spirit and Opportunity.

"The global dust storm in 2007 was the first major threat to the rovers since landing," said JPL's John Callas, project manager for Spirit and Opportunity. "We had to take special measures to enable their survival for several weeks with little sunlight to keep them powered. Each rover powered up only a few minutes each day, enough to warm them up, then shut down to the next day without even communicating with Earth. For many days during the worst of the storm, the rovers were completely on their own."

Image above: This graphic indicates a similarity between 2016 (dark blue line) and five past years in which Mars has experienced global dust storms (orange lines and band), compared to years with no global dust storm (blue-green lines and band). The horizontal scale is time-of-year on Mars. Image credits: NASA/JPL-Caltech.

Dust storms also will present challenges for astronauts on the Red Planet. Although the force of the wind on Mars is not as strong as portrayed in an early scene in the movie "The Martian," dust lofted during storms could affect electronics and health, as well as the availability of solar energy.

The Red Planet has been observed shrouded by planet-encircling dust nine times since 1924, with the five most recent planetary storms detected in 1977, 1982, 1994, 2001 and 2007. The actual number of such events is no doubt higher. In some of the years when no orbiter was observing Mars up close, Mars was poorly positioned for Earth-based telescopic detection of dust storms during the Martian season when global storms are most likely.

Shirley's 2015 paper in the journal Icarus reported finding a pattern in the occurrence of global dust storms when he factored in a variable linked to the orbital motion of Mars. Other planets have an effect on the momentum of Mars as it orbits the solar system's center of gravity. This effect on momentum varies with a cycle time of about 2.2 years, which is longer than the time it takes Mars to complete each orbit: about 1.9 years. The relationship between these two cycles changes constantly. Shirley found that global dust storms tend to occur when the momentum is increasing during the first part of the dust storm season. None of the global dust storms in the historic record occurred in years when the momentum was decreasing during the first part of the dust storm season.

Artist's view of NASA's Mars Global Surveyor. Image Credit: NASA

The paper noted that conditions in the current Mars dust-storm season are very similar to those for a number of years when global storms occurred in the past. Observations of the Martian atmosphere over the next few months will test whether the forecast is correct.

Researchers at Malin Space Science Systems, in San Diego, post Mars weather reports each week based on observations using the Mars Color Imager camera on NASA's Mars Reconnaissance Orbiter. A series of local southern-hemisphere storms in late August grew into a major regional dust storm in early September, but subsided by mid-month without becoming global. Researchers will be closely watching to see what happens with the next regional storm.

mercredi 5 octobre 2016

Satellites from NASA and NOAA have been tracking and analyzing powerful Hurricane Matthew since its birth just east of the Leeward Islands on Sept. 28.

On October 4, 2016, Hurricane Matthew made landfall on southwestern Haiti as a category-4 storm—the strongest storm to hit the Caribbean nation in more than 50 years. Just hours after landfall, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired a natural-color image that showed the western extent over the eastern tip of Cuba and the eastern-most extent over Puerto Rico.

Image above: On October 4, 2016, Hurricane Matthew made landfall on southwestern Haiti as a category-4 storm—the strongest storm to hit the Caribbean nation in more than 50 years. Just hours after landfall, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color image. At the time, Matthew had top sustained winds of about 230 kilometers (145 miles) per hour. Image Credits: NASA Earth Observatory image by Joshua Stevens.

At NASA's Goddard Space Flight Center in Greenbelt, Maryland the NASA/NOAA GOES Project combined infrared and visible imagery from NOAA's GOES-East satellite into an animation of Matthew. The animation of imagery from Oct. 3 to Oct. 5 shows Hurricane Matthew making landfall in Haiti and eastern Cuba then move toward the Bahamas.

On Oct. 5, there were many warnings and watches in effect on Oct. 5 from Cuba to the Bahamas to Florida.

A Hurricane Warning is in effect for the Cuban provinces of Guantanamo, Santiago de Cuba, Holguin, Granma and Las Tunas; the Southeastern Bahamas, including the Inaguas, Mayaguana, Acklins, Crooked Island, Long Cay, and Ragged Island; the Central Bahamas, including Long Island, Exuma, Rum Cay, San Salvador, and Cat Island; the Northwestern Bahamas, including the Abacos, Andros Island, Berry Islands, Bimini, Eleuthera, Grand Bahama Island, and New Providence. In Florida a Hurricane Warning is in effect from north of Golden Beach to the Flagler/Volusia county line and Lake Okeechobee.

A Hurricane Watch is in effect for the Cuban province of Camaguey and north of the Flagler/Volusia county line to Fernandina Beach. A Tropical Storm Warning is in effect for Haiti, Turks and Caicos Islands. In Florida a Hurricane Watch is in effect for Chokoloskee to Golden Beach, the Florida Keys from Seven Mile Bridge eastward, and Florida Bay.

At 11 a.m. EDT (1500 UTC), the eye of Hurricane Matthew was located near 21.8 degrees north latitude and 75.2 degrees west longitude. That's about 55 miles (90 km) north-northwest of Cabo Lucrecia, Cuba and about 105 miles (165 km) south of Long Island, Bahamas.

The National Hurricane Center (NHC) said "Matthew is moving toward the northwest near 12 mph (19 kph), and this motion is expected to continue during the next 24 to 48 hours. On this track, Matthew will be moving across the Bahamas through Thursday, and is expected to be very near the east coast of Florida by Thursday evening, Oct. 6.

Maximum sustained winds are near 120 mph (195 kph) with higher gusts. Matthew is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some strengthening is forecast during the next couple of days, and Matthew is expected to remain at category 3 or stronger while it moves through the Bahamas and approaches the east coast of Florida. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km)."

The minimum central pressure reported by both Hurricane Hunter planes was 962 millibars.

An unconfirmed wind gust of 155 mph (250 kph) was reported in Baracoa, Cuba, on the night of Oct. 4 as the eye of Matthew passed nearby.